Bio Chapter 5

G1, S, G2, M

Stages of the cell cycle

G1

The stage of the cell cycle where the cell grows and duplicates organelles

S

The stage of the cell cycle where the cell synthesizes DNA

G2

The stage of the cell cycle where the cell continues to grow, and is a critical checkpoint for the DNA

M

The stage of the cell cycle where the nucleus divides, creating two identical cells

Prokaryotic

Do prokaryotic or eukaryotic cells divide faster?

G0

Cells that do not go through mitosis

High

Is a low or high surface area-to-volume ratio better?

Makes transporting molecules more efficient

A high surface area-to-volume ratio does this

Chromosomes

Long continuous threads of DNA

46

How many chromosomes do humans have?

Histones

Proteins DNA wraps around

Chromatids

Tightly coiled chromosomes, shaped like half an X

Sister chromatids

Identical chromatids forming an X

Telomeres

"Caps" formed at the ends of chromatids to keep them together

Centromere

Holds together sister chromatids

Prophase, Metaphase, Anaphase, Telophase, Cytokinesis

Order of mitosis

Prophase

The stage of mitosis in which DNA condenses into tightly coiled chromosomes, the nuclear envelope breaks down, and centrioles move to poles and form spindle fibers

Metaphase

The stage of mitosis in which spindle fibers attach to each chromosome, which each line up along the cell equator (middle)

Anaphase

The stage of mitosis in which chromatids separate to opposite sides of the cell

Telophase

The stage of mitosis in which the nuclear membrane starts to form, chromosomes uncoil, and spindle fibers fall apart

Cytokinesis

The stage of mitosis in which animal and plant cells divide

Cell plate

Plants use this to divide during cytokinesis

Centriole

Plants do not have this organelle used in cell division

Internal & external factors

What regulates cell division?

Physical & chemical factors

External factors that regulate cell division

Growth Factors

Chemical signals sent out by cells that tell surrounding cells to divide

Internal factors

External factors trigger _________ that affect cell cycle

Kinases & Cyclins

The two most important internal factors

Apoptosis

Programmed cell death

Cancer

Uncontrolled cell division

Tumor

Clumps of cells that divide uncontrollably

Benign Tumor

Non-cancerous tumors that remain clustered together and do not spread throughout the body

Malignant Tumor

Cells that break away and spread through the body via the blood stream

Metastasize

The process in which tumors spread throughout the body

DNA Mutations

Cancer cells come from normal cells that have __________

Carcinogens

Substances known to cause cancer

Chemicals, radiation, inheritance, and bad luck

Causes of cancer include

Surgery

The first treatment of cancer

Radiation

Cancer is zapped with this to be treated

Chemotherapy

The last-resort cancer treatment that may kill both cancerous and healthy cells

Homeostasis

Organ systems work together to maintain __________

Cells, tissue, organ, organ system

The order animal structures are divided in

Tissue

Groups of cells working together to perform a function

Organ

Groups of tissues working together to perform a specific function

Organ Systems

Organs that carry out similar functions

Cell Differentiation

The process by which unspecific cells gain specific functions

They read only certain genes

How do cells become specific?

Stem Cells

Cells which can develop into a variety of specialized cell types

Totipotent

Located in a fertilized egg, can become any type of cell

Gene

A segment of the chromosome

Pluripotent

Located in embryonic stem cells, can become almost any type of cell

Multipotent

Located in adult stem cells, can become a closely related cell